This module provides access to the Windows Registry, the database that
stores information about all parts of your system and software.
Many operating system and application behaviors are controlled by Registry
data. The Win32::Registry module gives you a way to access and update registry information
with Perl. (Warning: Always be careful when making changes to the registry.
If vital system information gets changed by mistake, your system could become
inoperable. Always make certain you have a backup of your registry
before you start to make modifications.)

The Registry module automatically creates objects for the top-level registry
trees. These objects are created in the
main::
namespace,
and each key that you open or create is accessed via one of these root objects.
The four top-level objects are:

$HKEY_CLASSES_ROOT
$HKEY_CURRENT_USER
$HKEY_LOCAL_MACHINE
$HKEY_USERS

If you are outside of the main (default) namespace, you should package declare
the keys, i.e.,
$main::HKEY_USERS
.

The
Open
method creates new key objects for subtrees or subkeys under
another open key object. Initially, a new key is opened from one of the main
key objects, for example:

This example creates a key object
$CurrVer
for the
CurrentVersion
key for Windows NT. This key contains several values
for the version of the operating system. With the new key open, you can
read or change the values it contains (every key has at least one unnamed,
default value), or open and create subkeys.
The
Open
method can only create key objects for existing keys.

Registry values are represented in Win32::Registry functions by three
elements: the name of the value, the data type of the value, and the value
itself. There are several different data types for the values. Win32::Registry
defines the following constants for these types: